U.S. Pat. No. 6,930,506 B2 discloses a terminating resistor driver for high speed data communication. The driver circuit has a plurality of parallel units each comprising two resistors and an upper and a lower switch. The resistors are each connected to a transmission line with one end and connected to the upper or the lower switch, respectively, with the other end. The upper switch is further connected to an upper reference potential and the lower switch is further connected to a lower reference potential. A total impedance of all the resistors equals an impedance of the associated transmission line.
It is a challenge to provide a driver circuit with advantageous voltage margining functionality. It is a further challenge to provide a driver circuit with advantageous termination impedance matching functionality.